Method of treating food products



- Reissued Dec. 14, 1937 METHOD OF TREATING FOOD PRODUCTS AND RESULTING PRODUCT Samuel Henry Ayers and Charles W. Lang, Philadelphia, Pa., assignors, by mesne assignments, to Crown Can Company, Philadelphia, Pa., a corporation of Pennsylvania.

No Drawing. Original No. 2,054,066, dated September 15, 1936, Serial No. 629,719, August 20, 1932. Application for reissue September 2. 1937, Serial No. 162,210

15 Claims. (01. 99-155) This invention relates to the art of packing products generally classified in the fruit industry. In particular, it relates to methods for treating and packaging such products and to the resulting sealed container under a high vacuum ranging from about 16" to about 26", possess no foreign or cooked taste, maybe substantially free from rind oil, may contain no added sugar, have. taste P d P od cts. and flavor substantially the same as fresh juice The present invention is applicable to frui of like fruit naturally ripened to the same extent, products such as the juices of citrus fruits, in-v and, in the case of juices in which there is atendeluding tangerines, kumquats, tangerine limes, ency to separation of the liquid and heavier malimes, lemons, oranges, grapefruit, tangelo, citron, terial, this tendency is considerably diminished l0 grapefruit pomolo; juices of other fruits including so that no separation of clear liquid takes place. apple cider and grape and berry juices; and juices Such juices are further characterized by the fact of pulpy fruits such as those obtained from pinethat they are sealed with a minimum amount of apple, cantaloupe, peaches, tomatoes and the like. free air therein and the gas content in the sealed.

In the interest of brevity and certainty the excontainer contains materially less total gas, in-

pression fruit juices" as used herein is to be read eluding carbon dioxide and nitrogen, than is pres- 15 and understood as meaning and referring to any ent in corresponding juices in the same size conone or all of the foregoing or analogous sub- ,tainer and treated by methods heretofore in use. stances, unless indicated to the contrary. For example, orange juice, packaged according The present invention may be broadly described to the present method in a No. 1 size can having a as including the steps of suitably preparing and minimum juice contentof about nine and one? 20 placing fruit juices in suitable containers, subhalf fluid ounces, contained less than 5 cc. of total jecting the juices in the containers to the steriligas composed of less'than l of CO: with subzation action of steam under such conditions that stantially all the remainder thereof being nitrothe juices will be commercially sterilized without gen. Grapefruit juice similarly packaged gave the development of any noticeable cooked taste, substantially the same results. This gas content 25 closing the containers by means of the steam presis less than one-half the amount found in the sure therein and finally permanently sealing the same size containers of orange and grapefruit containers with steam therein under greater than juices packaged according to other methods in use pheric pressure. at the present time, and in the latter juices the Many variations of these important steps may ratio of the nitrogen to the CO: varied widely and 30 be made, and many additional steps may, sepawas higher than in the packages containing rately or collectively, be combined with the foreorange juice treated according to the present ingoing steps or variations thereof. For example, vention. the fruit juices are preferably concentrated be- The amount of oxygen existing, at the time of fore sterilization su'fliciently to compensate for sealing, as free air in the containers of orange 35 the diluting action of the steam which may conjuice treated by this invention, if calculated on the dense in the juice and container during and after basis of the nitrogen found in the container when sterilization. The juices may also bepartially dethe foregoing gas examinations were made, was, gassed preliminary to sterilization. They may on the average, less than 50% of the oxygen sim- 40 be, and preferably are, brought to a temperature ilarly estimated to have been present in containers between about 120 F. and about 140 F. before of similar size containing orange juice treated by sterilization. They may be, and preferably are, prior methods. subjected to vacuumization between about 16" The present invention will be described in conand 28" of mercury just priorto sterilization, and, siderable detail, so that it may be understood by 5 after sterilization and before final sealing of the those skilled in the art. For this purpose, orange containers, some of the steam pressure may be juice has been selected primarily-because it is released from the container with resultant ingenerally recognized as being quite diflicult to creased vacuum in the finally sealed container. treat and package in such a manner that the After the container is finally sealed, it and its conjuices will closely correspond in substantially all tents may be cooled at different rates. For ex-. respects to juices from fresh tree-ripened fruit, 50

ample, such temperature may be reduced to below altho it is easy to sterilize orange juice to prevent about 110 F. in about two minutes time. fermentation.

- 'Fruit juices treated according to the present The orange juice is extracted from the fruit invention are characterized by the fact that they in any suitable manner such as by cutting each are commercially sterile, are maintained in the orange into two halves and then reaming out the 5 pulp. The pulp may be squeezed out if desired, but some rind oil frequently accompanies the Juice in such case. screening apparatus may be employed for separating the larger sized pieces of pulp and foreign material from the juice.

The juice may be concentrated to compensate for the dilution resulting during sterilization. The concentration is preferably carried out by subjecting the screened juice at low temperature to a high vacuum. It has been found that in continuous operation about 120 gallons of orange juice per hour may be concentrated to the extent of about 10% by passing it thru tubes under a vacuum of from about 26" to about 28" of mercury, while the tubes are surrounded with steam at a temperature of about 150 F. This concentration involves the liberation of water vapor from the juice. This liberation may be permitted in such a'. manner that gases also are liberated and separated from the juice. Conveniently, the juice which has been heated as aforesaid, may be discharged into a chamber maintained under the high vacuum mentioned, and the water vapor and gases removed therefrom .while the juices may be pumped out for subsequent treatment.

The concentrated juice is then'placed in suitable containers, as by means of an ordinary filling machine, and the containers, after being provided with suitably valved covers. are heated so 'that the contents attain a temperature between about 120 F. and about 140 F. Then the juice is ready for sterilization.

Preferably the containers, with the orange juice therein at between about 120 F. and'140 F.,

till

are subjected to a vacuum of between about 16" and about 27" of mercury or more preliminary to sterilization. While this vacuumizing treatment may be omitted in some instances, it is preferable to use it' in most cases. Where vacuumizing is employed, the sterilization follows immediately thereafter. Steam ranging in temperatures between about 240 F. and about 260 F. is admitted into the container and is caused to penetrate into and to pass thru the juice thereby coming into contact with substantially all portions of the juice in the container, and causing violent agitation of the juice, as may conveniently be done, passing the steam up thru the liquid. The steam sterilizes the juice, raising the temperature thereof to between about 212 F. and about 225 F. and builds up a pressure within the container sufficient to close the valve when the connection between the container and the steam supply system is broken. The container is closed by means of steam pressure therewithin and is thereafter permanently sealed. Between preliminary closing and permanent sealing, the container may be vented, if desired, to release some of thesteam pressure and gases, with the result that an increased vacuum will be present in the finally sealed, cold container.

After the sterilization step has been completed.

the container and its contents may be quickly centration of the juice, the temperature of the' fruit juice preliminary to-sterilization, the ex- Any standard satisfactory some tent of vacuumization, and the temperature, pressure and amount of steam used during sterilization. In general, the higher the preheating temperature used, the lower may be the temperature and pressure of the steam, or the smaller may be the amount of steam required at a higher temperature and pressure for sterilization. The greater the amount of steam employed, the great er will be the amount of steam condensation in the container. The temperature and pressure of steam required to bring the juice to the predetermined temperature depends, to some extent, on the amount of vacuum or the absolute pressure existing in the container just before the steam is admitted. The amount of vacuum in the finally sealed container likewise depends to some extent on the amount of preliminary vacuum before sterilization, and the amount of steam and gases released from the container after sterilization.

Continuous production is made possible by the 140 F. in the final container, the containers are,

vacuumized between about 16" and about 28" of mercury. Steam at temperatures ranging between about 260 F. and about 240 F. is admitted into the thus vacuumized containers and contacts with substantially all portions of the juice and heats the same to between about 212 F. and about 225 F. within a period of around about fifteen seconds. The vacuum existing in the finally sealed containers at room temperature will range between about 16" and about 26" of mercury, but release of some of the pressure after the container is first closed and before it is finally sealed will insure vacua in the upper portions of this range.

It is important that the containers should be provided with means, such for example, as valves, thru which gases may be withdrawn from the container and thru which steam under pressure may be introduced into the container and its contents. Such a means may conveniently be capable of being closed by means of steam pressure in the container, and should be easily and readily sealed permanently against leakage of gases into or out of the container. Satisfactory results have been obtained with valved containers like those shown in U. S. Patent No. 1,728,533.

One form of apparatus which has been found satisfactory for practicing the present invention. is shown, described and claimed, in the copending application of John Mills, Serial No. 629,678, filed August 20, 1932.

Having thus described the present invention so that those skilled in the art may be enabled to practice the same, what'is desired to be secured by Letters Patent is defined in what is claimed.

What is claimed is:

1. The method of treating fruit juices which includes the steps of concentrating a quantity of fruit juice to about 90% of its original volume,

placing such concentrated fruit juice in a plurality of final containers, subjecting the fruit juice in the final containers and at a suitable temperature to the action of steam passing therethru at a sterilizing temperature, andseal- "ing all the containers includes the steps of with substantially the same pressure therein.

The method of pressure, closing the containers by permitting the steam pressure in the container to close thelatter,-and sealing the containers permanently with substantially the same high steam pressure in all the containers.

treating fruit juices which includes the steps of concentrating afrult juice at a. low temperature and under high vacuum, placing such concentrated fruit juice in final containers and while such juice is at a suitable temperature, exhausting gases from the con- 5. The method of after agitating and heating the juice in the containers by passing thereinto steam under high.

pressure,closing the containers by permitting the steam pressure in the container to close the latter, sealing the containers permanently with substantially the same high steam pressure in all the containers, and quickly cooling the containers and their contents below about 110 F.

6. The continuous method of treating fruit juice which comprises continuously performing I the steps of extracting the juice of .a fruit, screening the extracted juice to separate out the heavier pulpy particles and-foreign materials, and concentrating the screened juice to about 90% of its original volume at low temperature under high vacuum, then performing the steps of delivering the concentrated juice to the final juice containers, heating such containers and their contents to raise the temperature of the latter to between about 120 F. and 140 F., then performing on each container successively the from the container under high vacuum, passing steam under highpressure through the juice in the container immediately after the exhaustion of gases therefrom thereby agitating and heating the juice in the container to between about 212 F. and about 225 F., interrupting the introduction of steam into the container and permitting the steam pressure in the container to close each container with substantially a predetermined page in the final nently sealed.

' 7. In the which'gases are removed from a final container in the container, juice is heated by the steam to a temperature suflicient for' partial sterilization of the fruit time, and so a vacuum of above about 16" of mercury, and the gas content in the container is relatively small with a negligible amount of. free oxygen calculated on the basis of the nitrogen present.

8. 'In the which gases are removed from the final container steps .of correlating the temperature of the fruit juices in the conthat the fruit juices are heatedby the steam to between about 212 F. and about 225 F. within about fifteen-seconds time, and, when cold, the.

' fruit juice in the container has a volume not more than about greater than before the above described treatment, are sealed against gas leakcontainer under a vacuum of above about 16" of mercury, and the gas content in the container is relatively small with a negligible amount of free oxygen calculated on the basis of the nitrogen present.

9. Commercially sterile fruit juice under high vacuum in a sealed container and having color, taste, flavor and concentration characteristic of fruit juice which has been extracted from fresh 240 F. and about 260 F., followed by permanent sealing of the container with a relatively small amount of free air and with steam therein under pressure, the concentration of the juice in the final container at roomtemperature being substantially that of the juice before it was subjected to the step of concentration.

10. The method of treating liquid food stufls,

' particularly fruit juices which includes the steps of concentrating a quantity of liquid foodstuff to about 90% of its original volume, placing such concentrated iood stufi in a final container, passing steam at a sterilizing temperature into the food stuff in such container, while the food stuff. is at a suitable temperature, to exert a sterilizing action on the food stuff and to increase its volume to substantially that of the unconcentrated food stufi and sealing the container with steam pressure therein.

11. The method of treating fruit juices which includes the steps of agitating and rendering commercially sterile a partially concentrated fruit juice at a suitable temperature by passing steam thereinto, the steam condensing in the juice being suificient approximately to restore thepartially concentrated fruit juice to its unconcentrated volume, and finally sealing the juice in a container.

12. The method of treating fruit juices which includes the steps of agitating and rendering concentrated and de-gassed fruit juice at a suitable temperature by passing steam thereinto, the steam condensing in the juice being sufllcient approximately to restore the partially concentrated fruit juice to its unconcentrated volume, and finally sealing the juice in a container. 1

13. The method of treating fruit juices which includes the steps of partially concentrating fruit juice, agitating and rendering commercially sterile the concentrated fruit juice at a suitable temperature by passing steam thereinto, the steam condensing in the juice being suflicient approximately to restore the partially concentrated fruit juice to its unconcentrated volume and finally sealing the juice in a container.

14. The method of treating fruit of partially concentrating and de-gassing iruit juice, agitating and rendering commercially sterile the concentrated fruit juices at a suitable temperature by passing steam thereinto, the steam condensing in the juice being suillcient approximately to restore concentrated volume and tainer. v I y 15. The method of treating fruit juices which includes the steps de-gassing fruit juices, suitable temperature in a ing steam thereinto, the steam condensing in the juices being sufficient approximately to reits unconcentrated finally sealing the juice in a conraising the juice to a store the partially concentrated fruit juice to its unconcentrated volume. and finally sealing the container. SAMUEL HENRY AYERS.

CHARLES W. LANG.

juices which the partially or partially concentrating and 

